。
She didn't entirely share my opinion.
Literal
She [topic-は] me [with-と] completely same-opinion was [nominalizer-わけ] [topic-では] is-not.
~わけではない ('it's not that...') is a key hedging structure: it negates not the proposition itself but the strong inference one might draw from it. The bare 同意見ではなかった ('didn't share my opinion') would imply outright disagreement, but わけではない softens it to 'wasn't entirely in agreement' — leaves room for partial alignment. すっかり ('completely, entirely') sharpens the contrast: she didn't *fully* agree, with the implication that she partially did. This nuance is crucial for navigating Japanese conversations where blunt disagreement is often softened.